Electrical stimulation devices are used to deliver neurostimulation therapy to patients to treat a variety of symptoms or conditions such as chronic pain, tremor, Parkinson's disease, epilepsy, incontinence, sexual dysfunction, obesity, or gastroparesis. Neurostimulation may involve delivery of electrical pulses via one or more implantable leads that include electrodes located proximate to the spinal cord, pelvic nerves, or stomach, or within the brain of a patient. The electrical stimulation device includes a pulse generator, which may be implantable or external.
A clinician programs the electrical stimulation device to define one or more stimulation programs. Each program may specify stimulation pulse parameters such as voltage or current amplitude, pulse width and pulse rate, as well as electrode combinations and polarities. Some stimulation devices may deliver stimulation pulses via two or more leads, each of which may carry numerous electrodes. The clinician selects combinations of electrodes, on a single lead or among multiple leads, for delivery of stimulation pulses. In this manner, the clinician can direct stimulation energy to a particular stimulation site.